Containers within the meaning of the invention, in particular, are packaging means designed as containers for filling material of different types and especially bottles or bottle-like containers or cans or can-like containers. Printing colours or printing inks within the meaning of the invention are those colours or inks, especially in liquid or slightly viscous form, which can be processed with printing heads which preferably can be digitally selected and operate according to the ink-jet printing head principle.
Printing heads within this meaning, in particular, are printing heads having a plurality of printing nozzles or printing apertures for applying the printing colour or printing ink, for example in at least one row, and which can be electrically selected individually for applying the printing colour or printing ink and, for this purpose, have a pressure-producing element at the respective nozzle aperture, for example taking the form of an electrode or of a piezo element.
Devices of the generic type for printing containers using printing heads operating according to the ink-jet printing principle and under relative motion between the printing heads and the respective container during printing are known (DE 10 2007 036 752). A known device of this type has two transport systems in the form of two support rings concentrically arranged to each other about a vertical machine axis and rotatably drivable about this machine axis. At the outer support ring, container receptacles are provided, distributed at uniform and preset angular distances about the vertical machine axis. At the inner support ring, also at preset angular distances, printing head units are provided each with a printing unit having several printing heads. The multicolour print images are applied to the containers, each arranged at a container receptacle, on a printing section which corresponds to the angular range of the rotary motion of the support rings between a container infeed and a container outfeed, namely in successive printing steps wherein, in each printing step, a colour set of the respective print image is produced. During the respective printing operation, the support rings and thus the printing head units and containers are moved synchronously, i.e. in the same direction and with the same angular speed. The inner support ring is additionally designed for an oscillating rotary motion, namely in the form that, following the application of a print image or of a colour set onto a container, a further container is then printed with the same printing head unit.